Scientists worry fungus could wipe out bats, hope to stop spread

Rob Haneisen

Sunday

May 24, 2009 at 12:01 AMMay 24, 2009 at 4:36 AM

A deadly fungus threatening to wipe out every species of bat in New England has likely been found for the first time in MetroWest. Scientists researching white-nose syndrome found dead bats and bats with fungus-covered faces in underground aqueducts in Wellesley and Natick in late March.

Scientists in Massachusetts have found a fungus that is harmful to bats in Wellesley and Natick, the first time the deadly fungus has been found in that area of the state.

Researchers studying white-nose syndrome found dead bats and bats with fungus-covered faces in underground aqueducts in Wellesley and Natick in late March, according to Susi vonOettingen, endangered species biologist for the U.S. Fish and Wildlife Service New England Field Office. All previous discoveries of the fungus in Massachusetts had been farther west.

White-nose syndrome was discovered in 2006 in caves in Upstate New York and has spread rapidly throughout all populations of bats that hibernate over winter in caves. It is estimated that 1 million bats may have already died from the fungus, which causes bats to wake up early from hibernation when there is no food. They then sicken and die. The fungus does not affect people, and white-nose syndrome can likely only survive in cold climates, scientists studying the bats said.

Tom Kunz, a Boston University biology professor and director of the Center for Ecology and Conservation Biology, led the aqueduct search team along 5,000 feet of abandoned, brick-lined tunnel in late March.

"I didn't expect to find white-nose in here," he said.

Samples of the fungus were sent to a Wisconsin lab, and results could be back in the coming weeks. Kunz has seen plenty of bats infected with white-nose syndrome and what he saw in the tunnel was all too familiar.

"I would say it's white-nose fungus," he said.

Researchers still don't know where the fungus (which accumulates on the bat's nose, face and wings) came from, how exactly it kills the bats or how it spreads. What they do know is that there appears to be no stopping its devastation of every bat species from Maine to Virginia.

"There is no safe place for these bats in the Northeast," said vonOettingen. "If you think of it optimistically, we are at risk of losing 90 to 95 percent of all of our bats. A pessimistic view would say we lose 100 percent."

Kunz said it may be premature to make such a dire prediction.

"The mortality in some of those (hibernation) sites has been in the 90 to 95 percent range. I think we'll have considerably reduced bat numbers this summer but we'll know more in mid-June when the adult colony reaches its peak," he said.

How far south and how widespread the fungus reaches is key, Kunz said.

"We're looking at possible extinction of some of these species of bats if it continues to spread," he said.

A New England without bats could provide an easy environment for mosquitoes, which could increase the spread of some diseases including eastern equine encephalitis or West Nile virus, some experts said. But the more likely, immediate and local effect from a bat die-off would be a boost in pests that attack garden and farm crops.

VonOettingen said people in areas with bat die-offs would notice more night- flying insects, more garden pests and might have to use more pesticides on farm crops.

"A lot fewer people and a lot fewer kids will have an opportunity to witness bats in flight and feeding," she said. "That living animal is going to be gone from us, and to me that is as tragic as (the effect on) agricultural interests."

On May 5, 23 members of Congress, including John Olver, who represents central and Western Massachusetts, sent a letter to Secretary of the Interior Ken Salazar requesting more funds from the USFWS be dedicated to white-nose syndrome research. The secretary's office said last week they could not comment on the request because they had not yet sent a response to Congress.

VonOettingen said she has been informed that $960,000 of the USFWS budget has been allocated to a grant aimed at preventing species extinction, some of which may help study white-nose syndrome.

Kunz said a sum closer to $10 million is needed to research the bat-killing fungus and plans to testify before Congress next month on that subject.

Part of that letter sent to Salazar stressed the risks to human health if bats were wiped out because of the possibility of a mosquito population boom.

David Henley, superintendent of the Eastern Middlesex Mosquito Control Project based out of Waltham, Mass., said it would be difficult to pin mosquito population fluctuations on bat die-offs. Springtime flooding has more of an effect on mosquitoes, he said.

"Bats eat a lot of nighttime flying insects but most of their diet is much larger insects," Henley said.

Scott Soars, Massachusetts commissioner of Agricultural Resources, said a major bat die-off could hurt farming and crops.

"We are concerned about impacts on the bat population," Soars said.

Pests that affect crops including fruit trees often have a moth stage and moths are a common prey for bats. Though it's speculation, far fewer bats could mean more crop pests for fruit trees, Soars said.

Soars also said a bat die-off could provide an opportunity for other species to fill that night-flying insect predator niche.

Whatever the drop in the bat population might have on the world of crop-eating pests, it's clear that bats are responsible for eating tons of insects each summer.

According to Barbara French, science officer for Bat Conservation International based in Austin, Texas, as many as 1 million bats may have already been killed by the fungus. With most bats eating their weight in insects each night, those bats would have eaten 1.3 million pounds of insects in a season.

"We are talking about mass quantities of insects that won't be eaten by the bats that are dying," French said. "The consequences are going to be tremendous."

And don't expect bats to make a quick comeback if a cure is found or the fungus stops spreading.

"Bats are very slow reproducing mammals," French said. "They give birth, most of them, to only one pup per year. If you lose a colony of bats ... it would be a very slow recovery."

This week, bat and conservation experts will gather in Austin to share their research and discuss what to do next.

Kunz believes the fungus directly or indirectly weakens a bat's immune system but there are far more questions about how well the fungus can be spread outside of the Northeast. Even though the fungus prefers cold climate caves used for hibernating, it is not known if it could survive well enough to devastate much larger bat populations in the Midwest, Southwest and Deep South.

"Everybody is looking for a silver bullet and we haven't found it," Kunz said.

What vonOettingen is seeing baffles and saddens her.

In late January she visited two caves in New Hampshire. One was clean, filled with only healthy bats clustered together on the ceiling deep in hibernation. A cave a mile down the road was mostly clean, with about 10 percent of the bats showing signs of white-nose syndrome.

Last week she revisited those two caves and was devastated by what she saw. In the cave with a mild infection only a small portion of the bats remained and 90 percent of them had white-nose syndrome. In the formerly healthy and clean cave, a vast majority of the bats were sick.

"I thought, 'Why am I looking at skinny, dehydrated bats?"' she said. "This was all from a site we would have called clean. It is very depressing."

MetroWest Daily News writer Rob Haneisen can be reached at rhaneis@cnc.com or 508-626-3882.

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